Perhaps surprisingly, Mr. Shanley says writing the opera was easier than writing the film script. "I had people in black, talking endlessly," he says. "I had to use every trick in the book to make it cinematic."

"Doubt" has made him keen on opera. "I want to do it again," he says. "It has opened up a door." He even has a sure thing in mind: "I wish someone would commission me to do 'Moonstruck' as an opera. It was meant to be an opera."